Demis is a super hard negotiator who was the only person able to get bought while keeping full control. I think he's more than capable of doing business.

Jeff Dean may not care that much about business, as he spent all his life on scalability, but he understands more than most people the exact data needed to be collected to be able to train the neural networks for launching / improving products. He may not want to be CEO, but I don't think that's a bad trait for a CEO.